What are the most common causes of a 403 Forbidden error during authentication?

Common causes for a 403 Forbidden error during authentication include: 1. **Insufficient Permissions/Authorization:** The authenticated user account lacks the necessary access rights. 2. **IP Address Restrictions:** The server might be configured to only allow access from specific IP addresses, and the user's IP is not whitelisted. 3. **Account Status Issues:** The user account might be suspended, locked, inactive, or expired. 4. **Geo-blocking:** Access might be restricted based on the user's geographical location. 5. **Security Policies/Firewall Rules:** A Web Application Firewall (WAF) or other security measures might be blocking the request due to perceived malicious activity or specific request patterns. 6. **Missing/Invalid API Key or Token:** For API-based authentication, a required key or token might be missing, expired, or incorrectly formatted. 7. **Server Configuration Errors:** Misconfigurations in web server settings or application access control lists.